1. Field of the Invention
The invention is directed to a flexible subterranean well fluid welding habitat for entrapment of welding slag, sparks and the like when welding operations are performed on the uppermost end of casing, drill or work string, or the like.
2. Brief Description of the Prior Art
Subsequent to the drilling of a subterranean oil or gas well, whether such well be located inland, or on a well platform, drill ship, simisubmersible, or the like, the well is completed by introduction of a tubular conduit which is often time referred to as "casing". The casing is cemented in place as part of the completion operation.
Prior or subsequent to the introduction of one or more sections of casing conduit forming the casing string into the subterranean well, it may be necessary or desirable to perform a welding operation to one or more ends of the casing to affix, for example, a blowout preventor, or other component desirable to be fixedly secured to the casing conduit section. In many instances, such component will be affixed to such casing conduit member by welding operations well known to those in the industry. As a result of the flame discharge from the welding torch, during the welding operation, sparks, slag and other depris can be expected to be discharged into the air around the welding operation resulting in a serious fire hazzard during the welding operation. Such slag and sparks could touch off a fire or even worse, an explosion, since the casing often times will be introduced into a "live" well which, at any time, could become uncontrollable as a result of a leak or blowout of flammable fluids, such as natural gas, or the like. The present invention addresses this problem by providing a flexible well fluid welding habitat which not only entraps the slag and sparks during the welding procedure in an area which is isolated from the well fluids, but also provides a habitat for the controlled dissemination of such slags and sparks through the habitat and away from the welding operation in a safe and controllable fashion.
The relevant prior art of which applicant is aware is as reflected in the following U.S. Pat. Nos.:
U.S. Pat. No. 2,872,933, entitled "Airdrilling Rig Cover".
U.S. Pat. No. 3,308,266, entitled "Method and Apparatus for Welding of Rails".
U.S. Pat. No. 3,837,171, entitled "Inflatable Underwater Structure".
U.S. Pat. No. 3,946,571, entitled "Service Module for Environment".
U S. Pat. No. 3,991,583, entitled "Method of Providing an Underwater Enclosure".
U.S. Pat. No. 4,257,720, entitled "Apparatus and Method for Driving Members Into the Ocean Floor".